The Developmental Therapeutics Program (DTP), Division of Cancer Treatment, NCI, is engaged in a screening program to detect plant extracts which demonstrate anticancer activity in vivo and in vitro systems. Plants are collected world-wide and will be shipped to the Contractor selected as a result of evaluation of responses to this RFP for preparation of extracts according to protocol. Extracts will then be shipped to Government screening laboratories for evaluation, and plants showing preliminary activity will be re-extracted for confirmation testing. Confirmed active plants of interest for further studies are then recollected and assigned to a natural products chemistry laboratory for isolation of the active principles. The active materials from these plants are screened in additional test systems and if deemed of sufficient interest to the NCI program, become candidates for pre-clinical and ultimately clinical studies.